1. Technical Field
The present disclosure relates to a graphene transistor and a logic device, and more particularly, to a transistor in which graphene configured to form a channel region is doped with a specific conductive type, and to a logic device capable of forming ternary data by combining such transistors.
2. Description of the Related Art
Graphene is a carbon conjugate having an SP2 hybridized bond structure. Graphene shows a behavior different from that of each of materials which are conventionally described by solid-state physics, and a representative behavior is a zero-band overlap phenomenon. That is, the graphene has a semiconductor characteristic in which a band gap is almost close to zero, and a conduction band and a valance band form a conical shape within an extremely low range with respect to a Fermi level. This refers to Dirac cones.
Meanwhile, there is some limitation to manufacturing in an electronic device using the graphene. A most representative obstacle is Klein tunneling, and the Klein tunneling is a theory describing behaviors of electrons in the graphene and refers to a phenomenon in which the electrons in the graphene can move by tunneling irrespective of a barrier condition even when an energy barrier exists. Therefore, the graphene has a characteristic that is difficult to cause a rectifying operation by configuring a diode and the like. Also, such characteristic serves to a limitation to manufacturing in a transistor based on a p-n junction.
Further, a transistor, which is manufactured using a conventional semiconductor based on silicon and the like, performs an operation in two regions which are roughly classified.
First, such a transistor operates as a switch in a linear region. That is, when a gate voltage is applied to cause a strong inversion in a channel region and an amount of current between a source and a drain is small, the transistor serves as a switch that performs ON/OFF operations.
Second, such a transistor operates as a current source in a saturation region. When the transistor serves as a current source, it is used as an active load in a small signal region.
In a conventional digital semiconductor device, a transistor is used as a switch. Therefore, when an inverter or a buffer is configured, a transistor outputs only signals of two type due to ON/OFF operations. That is, there is a characteristic in which only a binary logic of “0” and “1” is output in a digital signal.
In recent years, a semiconductor device, which should process a large amount of information in the same area, has a limitation only by the use of a conventional binary logic. Consequently, there is an increasing demand for a memory and the like to implement other states in addition to binary logic states to process more information and store more information in a single logic device or memory unit.